This invention relates to a vehicle lift for use with automobiles and other vehicles.
Vehicle repair tasks such as repairing or replacing transmissions, clutches, differential gears, universal joints, brakes, or suspension components often require access to the underside of a vehicle and thus require that a mechanic be underneath a vehicle for long periods of time. Because being underneath a vehicle frequently requires a mechanic to contort his body and to be upside down or have his head back, the mechanic finds it difficult to concentrate for long periods of time and to apply proper torque or purchase to parts or fasteners on which he is working.
Conventional lifts for allowing access underneath vehicles have ranged from tracks with a pit beneath them in which the mechanic may stand, to compressed air actuated lifts frequently found in today's service station bays. Such pits are expensive to install because of the excavation required, and installation of hydraulic lifts allowing standing room is also expensive because of excavation requirements and the expense of components.
Other techniques for allowing access to the underside of vehicles include separate support stands which may be set in place after portions of the vehicle are raised, as well as compressed air actuated bumper jacks which may be moved into place to lift one end of a vehicle. Although such techniques are less expensive than the pit or the larger lift, the mechanic still must work in an awkward position, frequently on his back.
Access to under-hood portions of a vehicle is also often difficult when the vehicle is in the normal position because of the need to lean over fenders or bumpers in order to reach parts being repaired. Removal and replacement of parts is often difficult for the same reasons.
The above-described problems can be solved by lifting and tilting or rotating a vehicle for maintenance and repair. In recognition of this, a few methods have been devised for tilting vehicles when they are lifted, including a two-masted lifting apparatus as disclosed in U.S. Pat. No. 4,050,673 issued Sept. 27, 1977 to Nishimura. This patent teaches the use of a carriage on each mast for supporting the vehicle and a height difference detecting means on the carriages. Both carriages are independently hoisted up and down by separate driving means to raise the vehicle and tilt it.
Another approach is found in U.S. Pat. No. 3,850,409 issued Nov. 26, 1974 to Davis, et al., which teaches a dual jacking device for connection to one end of a vehicle. Two separate independently operated lifting cylinders are attached to the vehicle, one to each side, so that it may be tilted as it is lifted.
Another approach to lift and tilt a vehicle has been to employ a pair of portable cranes, each including a chain hoist, positioned at the front and rear of the vehicle, as disclosed in U.S. Pat. No. 3,428,191 issued Feb. 18, 1969 to Newswanger. Each crane has a portable support assembly for supporting the vehicle in the lifted position and allowing it to be tilted.
None of the above mentioned approaches rotates a vehicle a full 90 degrees. Snowmobiles have been lifted and fully rotated in accordance with U.S. Pat. No. 3,734,466 issued May 22, 1973 to Mason by mounting supporting assemblies on a snowmobile substantially in alignment with its center of gravity and hoisting the rotatably mounted assemblies by means of cables up posts to a position where the snowmobile may be rotated. The manually operated winch devices used to hoist the snowmobile may be inadequate to lift heavy automobiles, trucks or other vehicles, however, and the device in any event requires cranking one winch and then the other in increments with resulting increased labor costs, or the presence of two persons simultaneously cranking the snowmobile up the posts.